RESUMO
An increasing demand for esthetic restorations has led to the development of new ceramic systems. In-Ceram, a glass-infiltrated alumina ceramic has three to four times greater flexural strength than other ceramic glass material. Because of its high strength, In-Ceram has been suggested as inlay, crown, laminate veneer and core material for resin bonded fixed partial dentures. This clinical application requires a stable resin bond to In-Ceram core. The purpose of this study was to evaluate the shear bond strength between In-Ceram core and resin cements according to various surface treatments and storage conditions. The surface of each In-Ceram core sample was subjected to one of the following treatments and then bonded to Panavia 21 or Variolink II resin cement. ; (1) sandblasting with 110 micrometer aluminum oxide powder, (2) sandblasting and silanization, (3) sandblasting and Siloc treatment, (4) sandblasting and Targis link application. Each of eight bonding groups was tested in shear bond strengths after the following storage times and thermocycling. ; A) 24 hours storage in distilled water at 371C, B) 5 weeks storage in dis tilled water at 37 C, C) 5 weeks storage in distilled water at 371C and thermocycled 2,000 ther mocycling for every 10 days(totally 10,000 thermocycling) in 51C - 551C bath. The bond failure modes were observed with scanning electron microscope (SEM). The results were as follows : 1. The shear bond strengths of sandblasting group were significantly lesser than the other groups after 24 hours water storage. 2. No significant difference of bonding strengths was found between storage time conditions (24 hours and 5 weeks). The shear bond strengths showed a tendency to decrease in Variolink II bonding groups and to increase in Panavia 21 bonding groups. 3. After thermocycling, the shear bond strengths of all groups were significantly decreased (p<0.01) and Targis link group exhibited significantly greater strengths than the other groups(p<0.05). 4. Panavia 21 bonding groups exhibited significantly greater bonding strengths in sandblasting group(p<0.01) and silane group(p<0.05) than Variolink II bonding groups. 5. In observation of bond failure modes, Targis link group showed cohesive failure in resin part and silane group and Siloc group showed complex failure and sandblasting group showed adhesive failure between In-Ceram and resin.
